A slide fastener is an opening and closing device of articles utilized not only in daily necessities such as clothing, bags, shoes, and sundry articles, but also in industrial articles such as water storage tanks, fishing nets, and space suits.
FIG. 1 shows the structure of a common slide fastener. A slide fastener 10 is mainly composed of three portions: a pair of long tapes 11, a large number of elements 12 which are the engagement portions of the fastener attached by sewing along a side edge of each tape, and a slider 13 which controls opening and closing of a fastener by engaging and separating the elements 12. Moreover, for preventing the slider 13 from dropping off, a top stop 14 and an opening device 15 can be provided, and a pull-tab 16 can be attached to the surface of the slider 13. The opening device 15 may comprise an insert pin 15a and a retaining box 15c with a box pin 15b. The slider 13 cancels the engagement of the elements 12 while moving to the opening device 15 provided at the bottom of the long tapes 11, pulls out the insert pin 15a from the retaining box 15c, and separates the tapes 11.
Among the components of a slide fastener, elements, a slider, a top stop and a bottom stop, and an opening device are molded components generally manufactured by injection molding, and it is known that these components can be produced from polyamides.
For example, DE No. 3444813 describes a method for forming a slider from a glass fiber-reinforced polyamide by injection molding for the purpose of improving the durability to washing and ironing of a slider to be used for a slide fastener for bedclothes and the wear resistance to sliding of the slider (claim 1). In DE No. 3444813, it is described that the length of glass fibers is 4 to 8 mm, and the content thereof is 25% by weight or more (claim 1); it is described that a slider is subjected to recrystallization treatment after molding (claim 1); it is described that polyamide 6,6 is used as a polyamide (claim 6); and it is also described that a polyamide containing neither a lubricant nor a gliding agent is used, and the content of glass fibers is about 40% by weight (claim 5).
On the other hand, a method of metal plating an article made of polyamides is known, and National Publication of International Patent Application No. 2008-508399 discloses “a method of preparing a metal plated polyamide composition, characterized in that it comprises applying metal plating to an article comprising a polyamide composition comprising: (a) about 40 to about 95 weight percent of at least one polyamide, (b) about 5 to about 50 weight percent of at least one mineral filler, and (c) about 0.1 to about 10 weight percent of at least one plasticizer, wherein the weight percentages are based on the total weight of the composition” (claim 1). This patent describes, as a method of metal plating, a process involving etching the surface of an article with an acid such as a chromic acid/sulfuric acid blend, followed by depositing a plating catalyst such as tin-stabilized colloidal palladium particles on the surface, subsequent removal of the tin stabilizer, applying an electroless deposition of a layer of metal such as nickel or copper, and applying an electrolytic deposition (galvanoplating) of metals such as copper, nickel, and/or chromium (paragraph 0019). It is also described in this patent that glass fibers may be used as a reinforcing agent (paragraph 0016).
Moreover, Japanese Patent Publication No. H6-76668 discloses “a method for plating plastic comprising: when a surface of a plastic substrate is subjected to electroless plating, bringing the substrate surface into contact with a gaseous mixture mainly containing gaseous fluorine and an inert gas beforehand to etch or activate the surface” for the purpose of increasing the adhesion of a metal-plated film to the plastic surface (claim 1).